My 2p's worth is that you won't be able to adjust them without the whole shooting match fitted. Hazzy days said the same as the levelling on the xenons is part if the multiplex in the car where the halogens are not.
Could be wrong but that's what I've been told.
HD charge an eyewatering £1600 for xenons fitted plus another £700 if you want auto leveling and cornering.
I had oem touran xenon's that I fitted to my caddy van and I couldn't adjust the beam in that either, was fine as the weight in the rear was constant, I didn't have any problems with people flashing etc Si it was all good.
